The present invention generally relates to a control apparatus mounted on an armrest of a seat in a passenger plane, and more particularly to the structure of an operating section located on top of such an apparatus.
As shown in FIG. 3, a common passenger plane is equipped with seats each having an armrest A fitted with a control apparatus 20. The passenger on each seat is capable of listening to his or her favorite music or the sound of a picture selectively by operating the control apparatus 20 with a finger.
This control apparatus 20 has an outward appearance as shown in FIG. 4 and is constructed into a box-shaped unit having a cabinet 21 of resin. On top of the control apparatus 20 an operating section is situated to be manipulated by a passenger""s finger. The operating section is provided with operational indications 22. In FIG. 4, reference numeral 23 designates a cable connected to the outside.
When the control apparatus 20 is to be mounted on the armrest A, consideration is usually given to harmonization of the control apparatus 20 with the armrest A in terms of design. For example, the color of the cabinet 21 is selected to be identical with or to match that of the armrest A so as to avoid incongruity in color between the armrest A and the cabinet 21 to be exposed thereon.
The operating section of prior art control apparatus 20 of this type has a structure shown in FIG. 5 including a face plate 24 forming part of the cabinet 21, a switch sheet 25, and a circuit board 26.
The face plate 24 defines a plurality of throughholes 27 in each of which a switch piece 28 is retractably fitted. The switch sheet 25 is fitted with the operational indications 22 and covers the whole outer side of the face plate 24 including the switch pieces 28. The circuit board 26 has a plurality switches 29 each located to face a respective switch piece 28, and a circuit (not shown) for processing signals inputted through these switches 29.
When a passenger depresses a desired indication on the switch sheet 25 of the control apparatus 20 thus constructed with a finger, the corresponding switch piece 28 located inside of the depressed portion protrudes inwardly to depress the corresponding switch 29, thereby closing the contact of the switch 29. In this way, an operation signal corresponding to the operation performed by the passenger is outputted from the control apparatus 20.
Since passengers of a plane usually eat and drink at their own seats, water or drink spilt on the armrest A of a seat often wets the exposed operating section of the control apparatus 20.
The operating section of the prior art control apparatus 20 has openings or clearances such as the through-holes 27 as described above and hence is not sufficiently closed against liquid. For this reason, such water or drink spilt on the control apparatus 20 may cause the switch sheet 25 to be peeled off or may penetrate into the apparatus 20 thereby giving rise to any accident such as a short circuit.
Additionally, since the color of the cabinet 21 of the prior art control apparatus 20 is required to match that of the armrest A in terms of design, the manufacturer has to prepare various control apparatus with cabinets 21 in different colors, thus resulting in the problem of the increased cost as a whole.
The present invention is made in view of the foregoing problems of the prior art apparatus, and it is, therefore, an object of the present invention to provide a control apparatus which is imparted with a reliable waterproofness against liquid spilt thereon to prevent any possible accident such as a short circuit and which is capable of being mounted on armrests of different colors without incongruity in color though it offers limited color models thereby reducing the manufacturing cost as a whole.
To attain the above object, the present invention provides a control apparatus comprising a cabinet on a face of which an operating section is formed which is operable by contact, characterized in that at least a cabinet face plate forming part of said operating section comprises a light-transmitting plate covering all the other components of said operating section tightly and entirely and an optical contact-detecting unit is located inside of said face plate of said cabinet.
The control apparatus according to claim 1 of the present invention comprises a cabinet on a face of which an operating section is formed which is operable by contact wherein at least a cabinet face plate forming part of said operating section comprises a light-transmitting plate covering all the other components of said operating section tightly and entirely and an optical contact-detecting unit is located inside of said face plate of said cabinet.
With this construction, the operating side of the cabinet is tightly covered with the cabinet face plate reliably protecting the inside of the apparatus against liquid that may happen to be spilt on the apparatus with its waterproofness. When the user touches the cabinet face plate with a finger, the light passing through the cabinet face-plate is reflected by the finger touching the cabinet face plate and the reflected light is detected by the optical contact-detecting unit, whereby the contact of the user""s finger with the cabinet face plate is detected.
Furthermore, when the control apparatus is mounted on an armrest of a seat, the cabinet face plate exposed on the upper side of the armrest is transparent or translucent and hence is inconspicuous relative to the armrest in terms of color. Thus, the control apparatus does not exhibit any incongruity with an armrest of any color.
In the control apparatus according to claim 1, the cabinet face plate may be translucent and the optical contact-detecting unit may be located inside of the cabinet face plate immediately facing the cabinet face plate without any intervening member. However, the control apparatus according to claim 2 of the present invention further comprises a liquid crystal panel disposed inside of the cabinet face plate for displaying an operational indication.
With the feature of the control apparatus according to claim 1, an indication displayed by the liquid crystal panel can be seen through the cabinet face plate from the outside and, hence, there is no need to print any operational indication on the cabinet face plate or affix any printed sheet thereon. Additionally, since the liquid crystal panel enables any operational indication to be changed easily and hence copes with any change in operation.
In the control apparatus according to claim 1, the liquid crystal panel may be of a reflection type which reflects light from the outside to make the indications thereof visible. However, the control apparatus according to claim 2 further comprises a lighting unit disposed inside of the liquid crystal panel.
With the feature of the control apparatus according to claim 2, the liquid crystal panel displays indications by utilizing light from the lighting unit disposed inside thereof and, hence, such indications are visible even if the environment is dark.
In the control apparatus according to claim 2, the lighting unit may comprise an illumination plate for receiving light from a light emitting body within the thickness thereof as claimed in claim 3. With this feature, the inside of the liquid crystal panel is entirely illuminated at a substantially even luminance thereby ensuring clearer display of indications. Furthermore, since most of the back-light of the liquid crystal panel passes through the liquid crystal panel and the back-light is scarcely directed to the optical contact-detecting unit, the back-light does not interfere with the detecting operation of the optical contact-detecting unit.
In the control apparatus according to claim 4, a reflection-type photo-coupler comprising an infrared light emitting device and an light receiving device is adopted as the optical contact-detecting unit. This feature enables a finger operation of the user to be detected accurately without any interference which may otherwise be caused by light from the outside or back-light of the liquid crystal panel.
The control apparatus according to claim 5 comprises a plurality of optical contact-detecting units which perform detection at different timing from each other. This feature avoids an inconvenience such as a detection error due to mutual interference between the optical contact-detecting units.
In the control apparatus according to claim 6, the cabinet is a tight unitary member. With this feature, the inside of the control apparatus is reliably protected against liquid that may happen to be spilt on the control apparatus by virtue of its firm waterproofness.